Problem/background

Medtronic has identified that an unpredictable, but very small, subset of InSync III devices may develop unexpectedly high and variable battery impedances, which can reduce the battery voltage to a point where the current is insufficient to support pacing output. Reported harms to date include bradycardia, dyspnoea, complete heart block, weakness and dizziness. Medtronic has received one report of a patient death where it is possible, but unconfirmed, that this issue was a contributing factor.

There is no provocative testing that can predict which specific devices may fail, and there is no programming that can mitigate this issue. The failure results from the development of a resistive film on the cathode current collector. Development of the film is erratic and it is, therefore, not possible to identify a specific current drain above which the film will not develop and hence at which the devices are not at risk.

To date Medtronic has received 30 reports of devices affected by this issue, which represents 0.03% of those distributed worldwide, all of which have involved devices with implant duration over 53 months. Medtronic predicts the failure rate will be between 0.16% and 0.6% for the remaining active devices, with an associated mortality risk of 0.007-0.02%. This should be compared to Medtronic’s estimated average mortality risk presented by early device replacement of around 0.005%, although clearly this will vary significantly depending upon the patient circumstances.

Unfortunately the InSync III models are not supported by Medtronic’s Carelink network, and so it is not possible to review patients remotely.

In the UK nearly 6,000 potentially affected devices have been supplied between June 2001 and October 2010 when this product was discontinued, and therefore most devices can be expected to have exceeded 4 years implant duration. To date there have been two incidents associated with this problem reported within the UK.

Medtronic issued an FSN to affected hospitals on 10 November 2015 which includes patient management recommendations to mitigate the risk associated with this issue.

Independent distribution

Establishments registered with OFSTED

children’s services

educational establishments with beds for children

residential special schools

Please note: CQC and OFSTED do not distribute these alerts. Independent healthcare providers and social care providers can sign up to receive MDAs directly from the Department of Health’s Central Alerting System (CAS) by sending an email to: safetyalerts@dh.gsi.gov.uk and requesting this facility.

Enquiries

England

Send enquiries about this notice to MHRA, quoting reference number MDA/2015/038 or 2015/011/010/131/003.